Exhaust-fan



(No Model.) 2 Sheets-Sheet 1;

J. M. SEYMOUR, Jr. EXHAUST FAN.

No. 420,470Q Patentedfeb. 4, 1890.

e lshmgim c (No Model.) 2 Sheets-Sheet 2.

J. M. SEYMOUR. Jr. EXHAUST FAN.

No. 420,470. Patented Feb. 4, 1890.

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JAMES M. SEYMOUR, JR, OF NEXVARK, NEHV JERSEY.

EXHAUST-FAN.

SPECIFICATION forming part of Letters Patent No. 420,470, dated February4, 1890. Application filed March 21, 1888; Serial No. 267,925. (Nomodel.)

To all whom it may concern.-

Be it known vthat 1, JAMES M. SEYMOUR, J12, a citizen of the UnitedStates, residing at Newark, in the county of Essex and State of NewJersey, have invented certain new and useful Improvements inExhaust-Fans; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same. v

This invention relates to an improvement in the construction ofexhaust-fans, the object being to utilize the full force of the blastgenerated in the revolution of the fan by avoiding any possibility ofreturn or back currents of air near the periphery and center of thewheel, commonly produced with the ordinary form of fans and resulting inloss of power and a diminution of the air-current; and the inventionconsists, essentially, in a fan or wheel whose blades or, vanes. are of.such an outline that the wheel will be shaped in general after themanner of aconicalfrustnm; also, in a casing or box for the wheelcorresponding in general conical shape thereto, so as to be adapted toeontainit, the width of said casing from front to rear beingconsiderably less than its diameter across its face; also, in aconicalhub for the fan-wheel, substantially as described; and,furthermore, the invention comprises certain details and peculiaritiesin the construction, arrangement, and combination of parts,substantially as will be hereinafter fully described and claimed.

In the annexed drawings, illustrating my invention, Figure 1 is a frontelevation of my improved exhaust-fan and the conical casing thatsurrounds it, a portion of the latter'being broken away to better showthe fanblades. Fig. 2 is. a vertical cross-section of the same, showingthe fan located in the wall of abuilding and actuated by adynamo-electric machine. Fig. 3 is a detail view of one of the plates ofwhich the fan-casing is composed. Fig. 4 is a view showing my improvedfan provided with a conduit or channel for collecting the current orblast after it has been generated. Fig. 5 is a perspective of the framefor the casing. Figs. 6 and 7 represent modifications.

Similar letters of reference designate corresponding parts in all thefigures.

In rotary exhaust-fans of the common and most usual construction the fanrevolves within a cylindrical box, the ends of the fanblades beingparallel to the wall of the box and moving in close proximity thereto,and the wheel partaking, in consequence, of a cylindrical form. \Viththis structure andarrangement the best results are not attainable. Thisis due to the fact/that the centrifugal force causes a certain amount ofair which has entered the wheel to be driven back as a receding currentnear the periphery instead of passing through the wheel. In addition tothe loss of air by this peripheral back-current, the common constructionof wheels involves another disadvantage, in that a back-pressure iscreated by the incoming of air from without near the center of thewheel. It becomes a great desideratum, therefore, in the structure ofthe wheel to prevent this loss of air and this obstruction to the freeworking of the fan, and on the other hand to oblige every cubic inch ofair that enters the wheel to pass through it. My object, therefore, isto avoid these disadvantages by altering the common structure so as tocut off the peripheral back-current and permit the centrifugal force toact in unison with the propelling, and also to overcomethe back-draft inopposition to incoming currents. This is accomplished by inclining thewall of the fan-casing inwardlyor in a direction opposite to that inwhich the air passes through it, the diameter of the airingress end ofthe said casing being less than the diameter of its air-egress end. Inthis way that portion of the ordinary casing where the peripheralback-current takes place is done away with by being cut off, so tospeak, and thus the return-current avoided. Furthermore, the fan-bladesare made to correspond with the changein the casing. The fan is alsoprovided with a conical hub whose sides correspond in general directionwith the inclined wall of the fan-casing. The base of the cone, if it besolid, or itsinterior, if it be hollow, is interposed in the path ofoutside incoming air-currents, )reventing them from entering the fan andeffectually stopping a back-draft.

Such being a general description of the essential ideas of my invention,I will proceed to describe the detailed structure which I have selectedand exhibited in the drawings, by way of example only, as one mode ofcarrying out my invention.

A designates the skeleton frame-work of the fan-casing, said frame beingconstructed to afford a proper inclination for the wall of the casingand being adapted to receive sections or plates 13 B, which are rivetedor otherwise attached thereto. The series of plates B B constitute, whenfixed in place, the inclined wall of the fan-casing, which latter hasthe general form of a hollow conical frustum. I prefer to make thecasing sectional, as stated, it being easier of construction than onemade in a single piece, especially since the walls are inclined.

C denotes the shaft of the fan or wheel, around which are arranged theobliquely-set elongated radial vanes or blades C. The shaft C issupported in bearings a and b, said bearing a being located at thejunction of the radial arms a a a, fastened to that side of frame Ahaving the lesser diameter, and said bearing 1) being located at thejunction of arms I) I), which are attached to that side of frame Ahaving the greater diameter. (See Fig. 2.)

The fan-casing is designed to be located vertically at any desired pointin a buildingas, for instance, opposite the opening X in a wall Y, asshown in Fig. 2. The casing is secured to the wall by bolts passingthrough projections on the casing-frame and entering the wall near theopening X. A fan thus located can be used for the purpose of cooling orpurifying the atmosphere of a room or other apartment.

In order to conform the fan to the shape of the inclined casing, the endof each blade 0 will be cut off at an angle, as shown, so that the edgemay be parallel to the casing and capable of moving in proximity theretoduring the revolutions of the fan. Further, the fan is provided with aconical hub D, secured on shaft 0, the side of the cone beingsubstantially parallel to the casin I am limited to no special angle ofinclination for the easin g neither am I confined to an exactparallelism of casing and conical hub; but I reserve the liberty ofvarying the structure in those-respects, and explicitly state that thecasing may have any desired inclination and that the conical hub may ormay not be cor-" respondingly inclined. Said hub D may be hollow orsolid. It effectually prevents the entrance into the fan of thosecurrents of air which tend to rush into it from without when it israpidly rotated. This tendency of the incoming air is analogous to theaction of a mass of water, which, when rapidly rotated, shows adepression at the center of the surface of rotation. This tendency inthe case of a fan creates a back-pressu re which interferes with itseasy working. It is effectually avoided, however, by the use of theconical hub.

Any suitable actuating power may be used to drive the fan. An electricdynamo, as shown at E, Fig. 2, is a convenient means. It is supported ona bracket E, bolted to one of the arms ct, said arm being furnished withopenings, as shown, for the reception of the bolts. I have shown at F,moreover, in Fig. 2, a belt-connection with the fan-shaft C, so thatwhen desired the shaft may be driven by said belt instead of by thedynamo. In Fig. I the fan-casing and fan are represented on a diminishedscale, and in conjunction with them are shown two pipes, one G servingas an induction-pipe to carry air to the fan, and the other II as aneduction-pipe to carry air away therefrom for any purpose or use. Thepipe II is curved and the fan-shaft O is carried through the wall of thepipe and supported exteriorly thereto at one end by means of a standardI. The end of the shaft is furnished with pulley c for the applicationof a driving-belt. Said pulley c is seen also in Fig. 2. Fig. 4therefore shows only a modification in the arrangement of the fan orblower to adapt the same for new uses.

A machine constructed in accordance with the principles of my invention,as above described, may be used for forcing either air or liquids. InFigs. 6 and 7 are shown modifications in the structure of the casing andalso of the hub. In Fig. 6 I still have the cone-shaped hollow casing.The hub, however, is not coneshaped, like the hub D, but is straight, asat D. Thus itwill be observed that a straight hub may be usedbeneficially with the conical casing. Furthermore, in Fig. 7, instead ofhaving the casing with the inclinedwalls, I have the walls straight andthe casingconsequently of cylindrical form, as at B. The hub, however,is not straight, but is co11cshaped.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

In an exhaust-fan, the combination of the conical casing, the rotary fancomposed of radial vanes or blades whose ends are inclined, so as to beparallel to the casing, the drivingshaft. and the conical fan-hubthereon, the width of said casing from front to rear being considerablyless than its diameter across the face, substantially as described.

In testimony whereof I affix my signature in presence of two: witnesses.

JAMES M. SEYMOUR, JR.

Witnesses:

L. A. ZIEGLER, MARCUS NORRIS.

